Air sprayer for furnaces



June 12, 1934.; I T. w. PRICE 1,962,212

AIR SPRAYER FOR FURNACES Filed Sept. 18, 1930 INVENTOR 77201125012 fiZPrice.

Patented June 12, 1934 UNIT STATES PATENT OFFICE a I above the fire for thereby assisting the combustion of the fuel.

An object of the invention is to provide a device of this character adapted to be attached at a convenient point within the fire pot of a fur- 10 nace and having an opening at one side to receive air from without the furnace, a series of directed openings at the opposite side for delivering air in appropriate directions over the fuel, and having its interior constructed to provide a tortuous 10* path of efiicient character for the passage of the air so that the air will become highly heated in passing through the device.

A further and more detailed object is to provide an air sprayer device adapted for attachment onto the inside surface of a furnace door,

said device having an opening at its front side facing the door adapted for connection with an air delivery pipe extending through an opening in the door, and said device having a series of apertures arranged in fan like disposition at its rear side facing away from the door for the delivery of air over the fuel, and said device having front and rear chambers separated by a partition arranged directly between the front and '30 rear openings, the chambers being in communication in the upper portion of the device only and each having means to render tortuous the path of air therealong.

A further object is to so arrange the openings at the rear side of the device that air forced or sprayed therefrom will be directed at an angle upwardly with respect to the horizontal level of the fuel in the fire pot.

A further object is to so design the air feed 40 connection to the device that it will serve in part for holding the device connected with the furnace door.

Other objects and aims of the invention, more or less specific than those referred to above, will be in part obvious and in part pointed out in the course of the following description of the elements, combinations, arrangements of parts and applications of principles constituting the invention; and the scope of protection contemplated will be indicated in the appended claims.

In the accompanying drawing which is to be taken as a part of this specification, and in which I have shown merely a preferred form of embodiment of the invention:

Fig. l is a horizontal sectional view through the front or fire feed door of a furnace showing a device connected thereto in accordance with this invention, a portion of the device being broken away and illustrated in horizontal section for'better disclosing the detail arrangement of parts of the device, and

Fig. '2 is a vertical sectional view taken substantially upon the plane of line IIII of Fig. 1.

Referring to the drawing for describing in detail the structure illustrated therein, the reference character L indicates a front wall portion of a furnace within an appropriate opening of which is the metallic frame G of the fire door H, the door being hinged upon the frame as at 1 in the usual manner, these parts'being illustrated merely as a means of indicating the general location and manner of mounting the device comprising the present invention.

The air sprayer device with which this invention is concerned consists of a metallic casing 2, preferably formed of cast iron and being of the general rectangular form approximately as illustrated, including a front wall 3, a rear'wall 4, end walls 5 and 6, and top and bottom walls 7 and 8. The device is arranged so that the front wall 3 stands parallel to and in close proximity with the rear or inner wall 9 of the furnace door, being held thereto by suitable means such for instance as the screws or bolts 10 which extend through openings in the door and engage within threaded sockets provided upon said wall 3.

An air feed pipe 11 extends through a suitable opening provided in the door and is fixed within an openinglZ provided to receive it through the wall 3. i

The wall 3 is provided with bosses 13 for receiving the screws 10 and a similar boss 14 for receiv ing the pipe 11. These bosses abut against the inner surface of the wall 9 of the door and serve as spacing means to hold the wall 3 spaced an appreciable distance from the wall 9 so that the hot air circulating within the fire box of the furnace may pass freely between the walls 3 and 9 to thereby heat the wall 3.

A look nut 15 may if desired be provided upon the outer portion of the pipe 11 to thereby constitute said pipe as a clamp means co-operative with the screws 10 to hold the air spraying device rigidly connected with the door.

Exteriorly of the door the pipe 11 may extend in any manner, and in any direction, to a suitable source of air supply whereby air under an ap-- propriate pressure, as for instance from a fan blower, may be fed to the sprayer'device. In the present instance an elbow 16 is included in said pipe and a flexible portion as 17 continues from the elbow 16, thus providing means whereby the swinging movement of the door H may not be interfered with.

It is noted that the opening 12 for the admission of air into the air spraying device is at the lower portion of the device.

The rear wall 4 of the air spraying device has a horizontally extending section 18 adjacent its lower end flared downwardly and rearwardly so as to stand at an incline with respect to the remainder of said wall. The opposite end portions as 1919 of the section are rounded, and this entire section, including the rounded end portions 19, is perforated with a series of air passages as 2020 extending therethrough substantially at right angles to the rear surface of said section andend portions so that air moving outwardly through said passages under the pressure supplied through the pipe 11 will be directed not horizontally across the upper surface of the fuel within the fire pot of the furnace but at a desir able angle upwardly across the surface of said fuel, the air passages in the rounded end portions 19 serving to direct the air drafts in fan like form toward the side regions of the fire pots, but always at a suitable angle upwardly away from the surface of the fuel.

The arrangement for directing the air drafts at an angle upwardly across and away from the surface of the fuel is important since if the air drafts, which may be of considerable force received from the fan blower, are directed horizontally across the surface of the fuel they would tend to blow out the weaker flames struggling for life at the fuel surface, whereas by directing the draft at an angle upwardly there is operated a tendency to vacuum between them and the fuel surface serving to draw the flames upwardly and at the same time supply them with the desired amount of highly heated air.

The tendency to vacuum created above the draft, by reason of the broad expanse of the wall 4 and the inclined relation of the portion 19 and of the draft passages 20 at the lower edge of said wall, materially assists in maintaining the upwardly inclining flow of the draft after leaving the passages 20. And in this connection it is noted that there is no substantial expanse of wall surface extending below the passages 20 and that there is therefore no appreciable vacuum pull from this direction.

The only downward influences upon the draft after leaving the passages 20 is that which is induced by vacuum tendency adjacent the surface of the burning coals, and the relationship existing between the draft passages and the wall surfaces above and below them as just referred to, is such as to suitably balance with or counteract this influence and enable the draft to move across the fire bed at just the right angle of inclination to properly feed and lift the flames.

Within the interior of the air spraying device, and midway between the front and rear walls 3 and 4 there is provided a permanent partition 21 projecting rearwardly from the bottom wall 8 and extending to near the top wall '7, but leaving a passage-way 22 across its top edge between the chambers 23 and 24 defined at its opposite sides, the chamber 23 being in communication at its lower end with the opening 12 and the chamber 24 being in communication at its lower end with the air spraying passages 20.

The partition 21 extends entirely from the end wall 5 to the end wall 6 so that there is no communication between the chambers 23 and 24 except by way of the passage-way 22 in the upper portion of the device.

W ithln the chamber 23 there is provided a pair of horizontally disposed baffles 25 and 26, one projecting rearwardly from the wall 3 just above the opening 12 and the other projecting forwardly from the partition 21 at the upper edge of said partition.

Within the chamber 24 three horizontally disposed baiiles are provided, one, as 27, projecting rearwardly from the upper edge of the partition 21, another, as 28, projecting forwardly from the wall 4 a slight distance below the horizontal plane of the baffle 2'7, and the third, as 29, projecting rearwardly from the partition 21 between the horizontal planes of the baffle 28 and the air spraying openings 20.

The manner of mounting the casing 2 provides for the passage of heated air entirely around said device so that all parts thereof will become highly heated. The partition 21 within the interior of the casing prevents passage of air directly across the casing from the opening 12 to the openings 20, and the arrangement of baifies as indicated provides for the intimate contact of air with the heated metallic surfaces of the walls and the bafiies during its tortuous passage around the partition by way of the passage-way 22.

Thus the air which is forced into the furnace from the fan blower by way of the pipe 11 may be in considerable quantity and under appropriate pressure and yet it will be adequately heated before it reaches its point of exit at the openings 20 into the fire box.

All parts of the casing 2, including the partition and baffles therein, are preferably formed as a single integral cast metal member, though obviously they may if desired be separately made and connected together in any appropriate manner.

As many changes could be made in this construction without departing from the scope of the invention as defined in the following claims, it is intended that all matter contained in the above description, or shown in the accompanying drawing, shall be interpreted as illustrative only and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An air spraying device for furnaces comprising a casing having means by which to fix it in operative position upon an inner wall surface of the fire box of a furnace above the fire bed and having its wall adjacent to the furnace wall formed with an opening for the admission of air into the casing through an opening of the furnace wall, said casing having its wall which faces inwardly of the furnace made up of two portions one of which provides an inwardly facing imperforate substantially vertical surface of relatively great expanse and the other of which provides an inclined surface of relatively less expanse continuing at an angle downwardly from the lower edge of the first portion and facing in an upwardly inclining direction across the fire bed and having a series of air passages formed in substantially right angular relationship therethrough for the passage of air from within the casing.

2. An air spraying device for furnaces comprising a casing having means by which to fix it in operative position upon an inner wall surface of the fire box of a furnace above the fire bed and having its wall adjacent to the furnace tical than horizontal to thus face in an upwardly inclining direction across the fire bed, and said lower portion having a series of air passages formed in substantially right angular relationship therethrough side by side along the horizontal length of said portion in close proximity to the lower edge of the casing for the passage of air from within the casing.

THORNTON W. PRICE. 

